1. Field of the Invention
The present invention relates to a vacuum cleaner including a first dust separation section for separating dust in sucked dust-containing air, and a second dust separation section disposed on a downstream side of the first dust separation section, particularly to a vacuum cleaner in which the first dust separation section uses inertia of the dust to separate the dust.
2. Description of the Related Art
A cyclone vacuum cleaner which separates air from dust by centrifugal separation in a first dust separation section and by filter separation in a second separation section is known; see Jpn. Pat. Appln. KOKAI Publication No. 2001-104223.
This vacuum cleaner includes a dust cup whose upper part is opened, and a motor blower which brings the inside of this cup into a negative pressure. A filter is disposed in an upper opening of the dust cup. An intake port is connected to a peripheral wall of the dust cup. The intake port is connected to a draw-in port member which draws in the dust via an intake passage.
Dust-containing air drawn into the dust cup turns in this cup with operation of the motor blower. By this turning, heavy dust particles are separated from the air. The separated dust accumulates in the dust cup, and the air is sucked into the motor blower through a filter.
The dust which has accumulated in the dust cup soars every time the operation of the motor blower is restarted. The filter is directly engaged in the dust cup, and therefore the dust which has soared is attached to or entwined with the filter. Therefore, the filter is clogged at an early stage, thus the function of separation of the air and dust easily drops.
The cyclone vacuum cleaner which separates the air from the dust by the centrifugal separation in the first dust separation section and by the filter separation in the second separation section is also known; see Jpn. Utility Model Appln. No. 60-157686.
In this vacuum cleaner, the inside of a cylindrical dust collector body is divided into upper and lower dust collector chambers. A horizontal partition plate which assumes this division includes an exhaust cylinder which communicates with both the dust collector chambers in a middle part. A suction port in a tangent line direction is disposed in the lower dust collector chamber. The suction port and lower dust collector chamber form the cyclone type of first dust separation section. A filter is disposed in the upper dust collector chamber to cover a draw-in side of an exhaust fan. The filter and upper dust collector chamber form the second dust separation section.
When the exhaust fan is operated, the first dust separation section carries out the cyclone type of dust separation. At this time, the air is drawn in the exhaust fan through the filter of the upper dust collector chamber.
The dust which has accumulated in the upper and lower dust collector chambers soars every time the operation of the motor blower is restarted. The dust which has soared is sometimes attached to or entwined with the filter. Therefore, the filter is clogged at the early stage, and the function of the separation of the air and dust easily drops.
The vacuum cleaner using a pleated exhaust fan for filtering and separating the dust from the air is known from Jpn. Pat. Appln. KOKAI Publication No. 2002-306380.
A dividing section, which is a quadrangular frame, surrounds the exhaust filter. The exhaust filter has pleads that extend in vertical direction. The dust that sticks to the surface of the exhaust filter while the motor blower is operating can therefore easily come off and falls. The lower frame part of the dividing section receives and holds the dust falling from the exhaust filter. This decreases the area of effective filter region, inevitably reducing the capability of the exhaust filter. If the second dust separation section employs the pleated filter, its efficiency of separating dust from air will decrease.
The vacuum cleaner which separates the air from the dust by inertia separation in the first dust separation section and by filter separation with the pleated filter in the second separation section is known, from Jpn. Pat. KOKOKU Publication No. 61-22563.
The vacuum cleaner includes a partition wall including an opening for exposing a front part of a pleated main filter. This partition wall contacts a side periphery of a filter hold member. A bottom plate is integrally disposed in the partition wall, and is disposed opposite to the main filter from below. A primary filter disposed integrally with the bottom plate is disposed in an outer periphery of the partition wall. The primary filter includes a mesh section and an impermeable wall disposed opposite to a hose port. The hose port opposed wall is formed so as to divert an air current leading to the front part of the main filter from a coarse dust chamber in a dust collector case. A hose connection port of the dust collector case is disposed opposite to the hose port opposed wall.
In this constitution, the dust-containing air which has entered the dust collector case from the hose connection port collides with the hose port opposed wall. Therefore, the coarse dust in the air falls into the coarse dust chamber. On the other hand, the air flowing along the surface of the hose port opposed wall passes through the mesh section and inverts a flow direction. After flowing along a back surface of the hose port opposed wall, the air flows through the main filter.
In the technique for allowing the dust-containing air to collide with the hose port opposed wall to separate the air from the dust, a technique of using an inertial force of the dust in the air current to separate the dust is not taught. With the collision of the dust-containing air with the hose port opposed wall, turbulence is generated, and therefore windage is large. Additionally, since the air current goes by the hose opposed wall, the windage is large. Because of this, the function of the separation of the air and dust easily drops on an upstream side of the main filter.
An object of the present invention is to provide a vacuum cleaner in which a capability of the separation of air and dust can be inhibited from dropping and a cleaning capability can be improved.